JESS: A female’s libido (sex drive) and hormonal changes vary from month to month. These changes are different for different females too. So there could be a few reasons why a girl/woman feels more horny at certain times of the month.

Some females feel very horny JUST before their period begins. From a biological viewpoint,this is the time when a female’s body is ready to be impregnated. Her body is ready for fertilization — meaning it’s a good time for the egg to be fertilized by a sperm (from the male). This is the case “biologically,” whether or not you actually wish to get pregnant!

Another theory is that a female could feel hornier or sexier due to the increased blood flow and lubrication in her groin during that time of month. This feeling of being hornier can also help relieve PMS symptoms in some females (symptoms such as menstrual cramps). P.S. The latter applies to me :)